10.1021/acs.chemmater.6b05248.s001
Wilman Septina
Wilman
Septina
Rajiv Ramanujam Prabhakar
Rajiv Ramanujam
Prabhakar
René Wick
René
Wick
Thomas Moehl
Thomas
Moehl
S. David Tilley
S. David
Tilley
Stabilized Solar Hydrogen Production with CuO/CdS
Heterojunction Thin Film Photocathodes
American Chemical Society
2017
0 V RHE
band gap
champion electrode
faradaic efficiency
Stabilized Solar Hydrogen Production
1 M phosphate buffer solution
photocorrosion
material
Photoelectrochemical measurements
TiO 2 layer
energy conversion
hydrogen-producing photocurrents
n-type CdS buffer layer
water splitting
Film Photocathodes Cupric oxide
CuO
hydrogen evolution
sulfide surface
0.45 V RHE
record photovoltage
band alignment
2017-01-26 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Stabilized_Solar_Hydrogen_Production_with_CuO_CdS_Heterojunction_Thin_Film_Photocathodes/4634023
Cupric oxide (CuO)
is a promising material for large-scale, economic
solar energy conversion due to the abundance of copper, suitable band
gap, and ease of fabrication. For application as a photocathode for
water splitting, the main challenge is prevention of the inherent
photocorrosion in aqueous media. Photoelectrochemical measurements
of bare CuO thin films prepared by oxidation of electroplated Cu indicated
that the vast majority of the photocurrent in 1 M phosphate buffer
solution (pH 7) comes from photocorrosion of the CuO into metallic
Cu, with a faradaic efficiency for hydrogen evolution of ∼0.01%.
We found that deposition of an n-type CdS buffer layer underneath
a protective TiO<sub>2</sub> layer yielded a stable and efficient
photoelectrode, with the champion electrode giving 1.68 mA cm<sup>–2</sup> at 0 V<sub>RHE</sub> and an onset potential of ca.
0.45 V<sub>RHE</sub>. We attribute a favorable band alignment of CuO/CdS
for the record photovoltage obtained with this material and a high
conformality of the TiO<sub>2</sub> layer on the sulfide surface for
the high stability of hydrogen-producing photocurrents (faradaic efficiency
∼100%).